1. Field of Invention
The present invention relates to an environmentally-friendly exhaust device and more particularly to a filter screen assembly having multiple layers of filter screens for carrying out multiple filtering. An integrated process is employed for enhancing the efficiency of exhaust filtering or purification and achieving the environmentally-friendly effects.
2. Related Art
People nowadays frequently emphasize environmentally-friendly awareness, and exhaust from various sources contains a great amount of poisonous substances such as carbon monoxide, hydrocarbon and oxysulfide, etc.
Conventional exhaust devices employ sponge to absorb and filter the oil mist or vapor during the process of oil mist. Such method requires changing of the sponge very often, and it is even more troublesome to change the sponge absorbed with oil. Furthermore, the replacement process costs manpower and time. The need for replacing the sponge very often will also increase the cost and therefore the conventional devices and method are not economically effective.
Additionally, conventional method for separating oil mist from air is performed by filling the oil mist into a waste water pool and detergent is added into the waste water pool. Then, the waste water pool is stirred over and over again to mix the detergent with oil. The oil will dissolve in the water. Such mixing method requires very high costs and is also not economically effective.
An environmentally-friendly exhaust device is provided by the present invention for improving the above-mentioned drawback of economical ineffectiveness of the conventional exhaust filtering method and purification method.